Photovoltaic solar concentrators typically are used to generate electrical power by concentrating sunlight onto photovoltaic devices, thereby collecting sunlight from a large area and concentrating it on a relatively small area of solar cells. Therefore, high efficiency solar cells, such as gallium arsenide-based (“GaAs”) solar cells, may be used in place of less efficient (and less expensive) silicon solar cells, thereby producing more energy per unit area at a reduced cost.
Solar concentrators may be configured in various ways and typically include refracting optics, reflecting optics or various combinations thereof. Regardless of the concentrating optics used, excess heat must be removed and the solar cells must be protected from the environment. Therefore, the design process generally requires a compromise between the thermal and/or protective features. For example, prior art systems that utilize Fresnel lenses (refracting optics) require placing the solar cells in the back of an enclosure, which makes it difficult to remove excess heat, requiring a larger heat sink.
Furthermore, efficient operation of solar concentrators requires precise alignment of the optical elements with the solar cells. Indeed, a more precise alignment enables a higher degree of optical concentration, thereby reducing the aggregate solar cell cost. However, prior art solar concentrator designs typically require costly manufacturing steps to achieve precise alignment, while others sacrifice precision, and therefore efficiency, to reduce manufacturing costs.
Accordingly, there is a need for a solar concentrator that quickly and easily aligns the optical elements with the solar cells in an off-axis configuration, while providing the solar cells with the requisite thermal and environmental protections.